You might be right Martyn - it's just that I thought 128 was the CD quality... So if it's 192k then thats the one where if it's any higher you won't notice the difference...
Anyway, I just copied a track from a CD to the PC and converted it from WMA to MP3. Did it once at 192k (48,000Hz freq) and another one at 128k (44,100Hz)
The 192k MP3 is 9.21MB and the 128k one is 6.17MB
Haven't tried em for comparrison sound wise as my sound card on the PC is shit and the speakers are just as crap
